Magnetic field–induced pair density wave state in the cuprate vortex halo

Decoding the halo pattern Magnetic fields can cause the formation of vortices in a superconductor. In cuprate superconductors, the vortex cores are surrounded by “halos,” where the density of electronic states exhibits a checkerboard pattern. Edkins et al. used scanning tunneling spectroscopy to take a closer look into the halos. The results revealed that the patterns correspond to an exotic state called the pair density wave, in which the density of finite momentum Cooper pairs is spatially modulated. Science , this issue p. 976